Pile driving apparatus



1965 J. w. CORFIELD FILE DRIVING APPARATUS 2 Sheets-Sheet 1 Filed Aug. 27, 1962 0 W, i. fii

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INVENTOR. Joseph W Corfl'e/d Af/ORNEYS.

Aug. 3, 1965 J. w. CORFIELD PILE DRIVING APPARATUS 2 Sheets-Sheet 2 Filed Aug. 27, 1962 0 mM Tr mm V N Q h W m AUORNEYJ.

United States Patent 3,197,967 PILE DRIVING APPARATUS Joseph W. Corfield, Long Beach, Calif., assignor of onehalf to Guy F. Atkinson Company, South San Francisco, Califi, a corporation of Nevada Filed Aug. 27, 1962, Ser. No. 219,690 Claims. (Cl. 61-53.68)

This invention relates generally to apparatus and devices for driving pile shells into the ground.

As is well known to those familiar with pile driving practices, it is common to construct concrete piles by driving a metal shell into the ground, after which the shell is filled with concrete. Various apparatus or devices have been used for the driving operation, such as special mandrels that are inserted into the shell. The present invention pertains to such driving devices and it is an object of the invention to provide an improved device of this type which is more effectively engaged with the shell for delivering driving impacts.

Another object of the invention is to provide apparatus of the above character in the form of an expansible unit which is lowered into the bottom of a driving shell, and which can be manipulated to expand with formation of a swaged driving shoulder on the shell, and to retract to enable removal of the unit.

Additional objects and features of the invention will appear from the following description in which the pre- 3,197,967 Patented Aug. 3, 1965 URE 3 ready for a driving operation, with the unit 12 having been expanded to form a driving connection with the lower portion of the shell. This driving connection is by virtue of the swaged-out wall portion 16.

FIGURES 5-8 show one suitable construction for the unit 12. Both FIGURES 5 and 6 show this uniit inserted into the shell. In general the unit consists of a body part 17 which is inserted into the lower end of the cylindrical core 10, and secured thereto by suitable means such as the pin 18. Below the body 17 there are a plurality of segmental metal dogs 19 adapted to be expanded and retracted by cam means, as will be presently explained. Below the dogs there is an annular cam member 21, which performs an expanding operation, and an inner cam member 22, which performs a retracting operation. Cam member 22 is in the form of an enlarged head on the lower end of the rod 23. This rod extends through a central opening in the body 17, and is threaded to receive the retention nut 24.

The upper end of the cam member 21 is formed to provide the cam surface 26, which conforms to a truncated cone. This surface is adapted to engage complementary cam surfaces 27, likewise conforming to a truncated cone, and formed upon the lower sides of the dogs 19. The upper end of the cam member 23 is formed to provide the cam surface 28 which conforms to a trunferred embodiment has been set forth in detail in con FIGURE 1 is a side elevational view showing apparatus in accordance with the present invention.

FIGURE 2 is a side elevational view showing a conventional pile shell such as may be driven by use of my invention.

FIGURE 3 is a side elevational view showing the pile shell of FIGURE 2, with the apparatus of FIGURE 1 inserted therein.

FIGURE 4 is the same as FIGURE 3, but shows the condition of the shell after driving relation has been established.

FIGURE 5 is aside elevational view in section illustrating the driving unit constituting the lower portion of the apparatus shown in FIGURE 1.

FIGURE 6 is the same as FIGURE 5, but shows the parts in a different operating position.

FIGURE 7 is a cross-sectional view taken along the line 77 of FIGURE 5, and showing the driving dogs in retracted position.

FIGURE 8 is a plan view of the driving dogs in their expanded position.

FIGURE 9 is a cross-sectional detail taken along the line 9-9 of FIGURE 6.

FIGURE 10 is a detail in section showing a construction in which keys are omitted.

The apparatus illustrated in FIGURE 1 consists of an extended core portion 10, having a driving head or a cap 11 attached to its upper end. Attached to the lower end of the core 10, there is a driving unit 12, which is adapted to establish driving relation with an associated pile shell.

FIGURE 2 illustrates a typical pile shell with which my invention may be employed. The body 13 of the shell is a cylindrical tube which may be of welded construction, and which may have a length dependingupon requirements. The lower end 14 constitutes a driving tip and is constructed to be driven into a ground formation.

FIGURE 3 illustrates the apparatus of FIGURE 1 inserted into the shell of FIGURE 2. Number 15 represents a supporting platform or plate upon which the tip 14 rests. FIGURE 4 represents the assembly of FIG- cated cone, and which in section extends substantially at right angles to the surface 26. Another abutment surface 29 is formed on the upper end of the cam member 21. This surface likewise conforms to a truncated cone, and in section is parallel to the surface 28. The lower sides of the dogs 19 are formed to provide additional surfaces 31, conforming to a truncated cone, and extending generally parallel to the surfaces 28 and 29. Surfaces 31 are adapted to cooperate with either the surfaces 28 or a 29, under different operating conditions.

Each of the dogs 19 preferably has its upper side provided with a dove-tail keyway 32, and the body 17 is machined to provide similar inclined keyways 33. Corresponding keyways are engaged by the double dove-tail keys 34. The keyways and keys are distributed generally in the manner shown in FIGURES 5 and 6, whereby when the dogs 19 are expanded, the movement of each dog is on a line of direction inclined to the axis of rod 23, by an angle corresponding to the angle made by surfaces 28 and 29, in section, which in this particular instance is 45.

In the retracted position of the dogs 19 shown in FIGURE 5, their inner ends are brought against the rod 23. The member 22 has an annular shoulder 36 which is in engagement with the limiting shoulder 37 on the member 21, for full retracted position.

The dogs 19 are expanded by downward movement of the core together with the body 17. Assuming that the shell 13, the tip 14 and the cam member 21 remain stationary during such movement, the cam surfaces 27 on the dogs are cammed outwardly by engagement with the cam surfaces 26, thus bringing the dogs into engagement with the adjacent rounding portion of the shell 13. Further downward movement of the body 17 causes the dogs to swage the shell outwardly in the manner shown in FIGURE 6. Here the outwardly swaged annular portion 16 of the shell includes the substantial annular shoulder 38, which conforms generally to a truncated cone, the slope angle of which is in excess of 45.

When expansion of the dogs has been completed as shown in FIGURE 6, shoulders 39 upon the upper sides of the dogs are in driving relation with an annular shoulder 41 formed on the body 17. Further outward movement of the dogs is also limited by engagement of the arcuate shoulders 42, with the annular surface 43 of the body.

FIGURE 8 illustrates the pattern of the dogs when they are completely expanded.

When it is desired to retract the dogs at the end of a driving operation, upward pull is exerted upon the core 10 and the body 17 relative to the shell 13, and this causes the cam member 22 to be moved upwardly against the dogs. This brings the cam surfaces 28 and 31 together, with the result that inward camming force is applied to the dogs to retract them from the swaged-out portion 16. It will be noted in this'connection that the outer ends of the dogs are tapered to facilitate their retraction. In other words, the outer surfaces 44 are inclined with respect to the surfaces 27. Further upward movement of the core it brings the dogs tocornplete retracted position, at which time they occupy the pattern shown in FIGURE 7. Thereafter the core together with the lower unit, may be retracted from the shell.

Operation of the apparatus is as follows. The core together with the lower expansible unit is lowered into the pile shell to bring the unit to the lower end of the shell. Thereafter further lowering movement of the core tends to expand the dogs into engagement with the shell. Impact or pressure can now be applied to the top of the core whereby the dogs are driven outwardly to form the swaged portion 16, and to establish good driving connection with the shell. This assembly is then used for a driving operation, with driving impacts being applied to the head 11, and with the entire assembly being driven to the level desired. After driving has been completed, suitable hoist means is applied to the head 11, and then upward pull is applied to the core whereby the dogs 19 are retracted, thus permitting the entire core and driving unit to be withdrawn from the shell. Concrete and reinforcement are now introduced into the shell.

It will be apparent from the above that my apparatus can be readily assembled with pile shells and a good driving relation established which would deliver impact energy to the lower end of the shell near the tip. At the end of the driving operation the apparatus can be readily retracted, thus leaving the shell ready for receiving concrete and reinforcement. The swaged-out portion 16 is an asset to the finished pile, because it provides better interlock between the shell and the concrete.

In the foregoing I have described the dogs as having key connections with the body 17. It will be evident that in place of such key connections, simple cam surfaces can be provided to obtain the motions desired. Thus as shown in FIGURE 10, the upper surfaces 19a on the dogs may engage a slide along the conical surface 17a on the body.

I claim:

1. In apparatus for driving a pile shell into a ground formation, wherein the shell is tubular and has a driving tip at its lower end, a driving unit adapted to be positioned within the shell at its lower end and adapted to receive driving impacts, said unit including a plurality of segmental and radially movable driving dogs disposed about the unit, said dogs having downwardly facing driving faces, and means for radially expanding and retracting the driving dogs, the dogs when expanded serving to swage the shell outwardly to form a driving shoulder engaging said faces to transmit downward driving impacts from the unit to the shell, said driving faces being disposed at an acute angle toa plane normal to the vertical axis of the unit.

2. Apparatus as in claim 1 in which said means for expanding and retracting the dogs includes two cam members, one of which is in the form of an annulus disposed below the dogs and having a dog engaging cam surface at its upper end for forcing said dogs outwardly of said axis, and the other of which is disposed within said annulus and is provided with a cam surface at its upper end adapted to engage the dogs and move them inwardly toward said axis.

3. in apparatus for driving a pile shell into a ground formation, wherein the shell is tubular and has a driving tip at its lower end, a driving unit adapted to be positioned within the shell at its lower end and adapted to receive driving impacts, said driving unit including a body, a first cam member disposed below the body and secured to the same, a second cam member in the form of an annulus surrounding the first cam member, upwardly faced concentric annular cam surfaces formed on the upper ends of both said cam members, said surfaces being oppositely sloped with respect to a plane normal to said axis, a plurality of segmental-shaped dogs movably disposed about the vertical axis of the driving unit and between said body and said cam members, cam surfaces formed on the lower sides of said dogs and adapted to engage the cam surfaces on the upper ends of said cam members, and camming means acting between the lower end of the body and said dogs and including surfaces in camming engagement extending generally parallel to the cam surfaces of said first cam member downward move- .ment of the body relative to the second cam member causing said dogs to be cammed to expanded position, and upward movement of said body serving to cause the first cam member to engage the dogs to retract the same.

4. Apparatus as in claim 3 in which the cam surfaces formed on the first and second cam members are sloped at an angle of with respect to each other.

5. Apparatus as in claim 3 in which said second cam member has two upper annular and oppositely sloped concentric surfaces conforming to truncated cones, the outer one of said last-named surfaces being a cam surface and the inner one forming a dog engaging abutment.

References Cited by the Examiner UNITED STATES PATENTS 848,395 3/07 Raymond 6153.72 1,413,503 4/22 Stevens 61-53.6 X 1,719,720 7/29 Olsen 15380 1,945,079 1/ 34 Riemenschneider l5380 X 2,847,830 8/58 Smith 6l-53.72

CHARLES E. OCONNELL, Primary Examiner. JACOB SHAPIRO, EARL J. WITMER, Examiners. 

1. IN APPARATUS FOR DRIVING A PILE SHELL INTO A GROUND FORMATION, WHEREIN THE SHELL IS TUBULAR AND HAS A DRIVING TIP AT ITS LOWER END, A DRIVING UNIT ADAPTED TO BE POSITIONED WITHIN THE SHELL AT ITS LOWER END AND ADAPTED TO RECEIVE DRIVING IMPACTS, SAID UNIT INCLUDING A PLURALITY OF SEGMENTAL AND RADIALLY MOVABLE DRIVING DOGS DISPOSED ABOUT THE UNIT, SAID DOGS HAVING DOWNWARDLY FACING DRIVING FACES, AND MEANS FOR RADIALLY EXPANDING AND RETRACTING THE DRIVING DOGS, THE DOGS WHEN EXPANDED SERVING TO SWAGE THE SHELL OUTWARDLY TO FORM A DRIVING SHOULDER ENGAGING SAID FACES TO TRANSMIT DOWNWARD DRIVING IMPACTS FROM THE UNIT TO THE SHELL, SAID DRIVING FACES BEING DISPOSED AT AN ACUTE ANGLE TO A PLANE NORMAL TO THE VERTICAL AXIS OF THE UNIT. 